This application relates generally to a method and system for monitoring and improving vehicle performance, efficiency, and other vehicle operating parameters in a vehicle by altering one or more of those parameters, for example, to reduce fuel consumption or to obtain other benefits.
Since at least 1996, every passenger car and light-duty truck sold in the United States has had a computer diagnostic data connection port, such as an OBD1, OBD2/OBD-II, or SAE-J1962 port. Most heavy-duty trucks currently sold in the United States also include a computer diagnostic port, usually referred to as a J1708 port or a J1939 port. Some vehicles also include one or more additional data ports, sometimes located in the passenger compartment, the trunk, or the engine bay. These data ports permit a mechanic, vehicle operator, or other user to connect to the vehicle and retrieve vehicle diagnostic data and operating parameters, that is, data about the vehicle, including engine, fuel system, brake system, and other data. Scan tools have been developed to permit mechanics and repair technicians to connect to the vehicle and monitor sensor data in real time as well as read and clear trouble codes and reset engine operating data and learned values. Some advanced scan tools even allow the mechanic to temporarily test vehicle components by actuating solenoids, altering fuel injection timing and/or open or close fuel injectors, altering ignition/spark timing parameters, altering variable valve timing parameters, altering variable displacement systems (for example, change cam phaser parameters), altering fuel pressure or fuel pump output parameters, commanding the transmission to stay in a specific gear, locking/unlocking the torque converter, altering transmission shift points, gear ratios, line pressure, shift firmness, or other transmission properties and numerous other tests for many vehicle components. Existing scan tools often are not designed to perform these kinds of tests while the vehicle is moving, and make it very difficult (and dangerous) for a mechanic or repair technician to perform these tests while driving the vehicle.
Many modern vehicles today also incorporate more advanced technologies such as cylinder deactivation, variable displacement, variable valve timing, dynamic exhaust flow controllers, hybrid electric systems, or even fully electric systems that may include battery packs, fuel cells, solar cells, or other electric fuel systems. Some of these technologies can reduce fuel consumption by deactivating cylinders or altering engine displacement in a predetermined way or, in the case of hybrid vehicles, completely turn off the combustion engine during idle or low acceleration periods.
Technologies such as variable valve timing can improve engine power and fuel efficiency by altering valve lift, duration, position, or overlap. This is typically done using a mechanical system controlled by the vehicle engine electronic control module. Many existing technologies implement variable valve timing, including cam switching, cam phasing, oscillating cam, eccentric cam drive, three-dimensional cam lobe, two shaft combined cam lobe profile, coaxial two shaft combined cam lobe profile, helical camshaft, or even camless engine designs where a camshaft is not used to control valve timing. These systems can be electro-mechanical, hydraulic, stepper motor, or pneumatic in nature. Regardless of the actual mechanical system used in the implementation of variable valve timing, the net effect allows the engine to produce greater power when needed while also being more fuel efficient by varying the valve timing (for one or more intake or exhaust valves or both or some other combination of valves) at low engine speed versus high engine speed for example.
Technologies such as variable displacement (also known as cylinder deactivation) can improve engine power and fuel efficiency by altering the effective engine displacement, usually by way of physically disabling air flow into or out of a predetermined cylinder or range of cylinders. This is distinct from variable valve timing technology, as it does not vary the actual valve timing (which has the net effect of changing the cam profile in real time), but rather typically involves completely stopping all valve activity on a predetermined deactivated cylinder. Many implementations exist for variable displacement cylinder deactivation. One such implementation alters oil pressure to collapse lifters so that the valves cannot be actuated. Another utilizes multiple locked-together rocker arms per valve, which can then be unlocked to completely disable valve activity.
Technologies such as variable intake geometry (known by various names, including a variable-length intake manifold, variable intake manifold, and variable intake system) seek to improve engine power and fuel efficiency by altering the length of the intake manifold runner or intake tract. This can be done, for example, using a valve that diverts air flow through either a shorter or a longer intake port, each having a different length or volume. Other methods implement variable intake geometry, but regardless of the technology used, variable intake geometry can be useful to effect different air flow properties such as swirl and pressurization at different engine speed ranges.
Other technologies such as dynamic exhaust flow control can improve engine power as well as affect the exhaust tone, noise and sound. For example, some vehicles utilizing dynamic exhaust flow control keep the engine exhaust restricted so as to flow through additional muffling devices to reduce noise. Then, when the vehicle operator requests additional power or acceleration (i.e. by way of the accelerator pedal), the vehicle unrestricts the exhaust flow to provide additional power, usually with the side effect of increased exhaust noise. The additional exhaust noise may or may not be desirable, depending on personal preference. Typically, the vehicle limits the unrestricted exhaust flow operation to predetermined engine RPM ranges or predetermined minimum acceleration pedal positions, or other predetermined limits based on other vehicle operating parameters.
These changes and technologies are typically executed by installing additional mechanical and electrical vehicle control systems as well as by calibration modifications through the electronic control modules such as the engine control module as factory original equipment. Typically, vehicle manufacturers provide diagnostic test and control commands, available through a data port, to test these systems and technologies in the event of a failure or problem (for example, by actuating cam phasers or fuel injectors). Nevertheless, these more technologically advanced and fuel efficient vehicles can also be supplemented with an additional system to further reduce fuel consumption and improve fuel economy, vehicle performance, and efficiency.
In the past, many different systems and devices have been created to improve the power, performance, efficiency, fuel economy and gas mileage of a vehicle. Often these systems are mechanical in nature and involve installing a device into the intake piping to help regulate airflow or installing aftermarket fueling systems or modifiers such as water or methanol injection. Some systems need to be spliced into the wiring harness so that they sit between the engine control computer and the engine's sensors. By altering sensor voltages, these kind of systems can then “trick” the engine control computer into thinking the sensor is reading a different value than is actually present. Given the altered sensor data, the engine control module may then decide to utilize different fuel parameters. Other kinds of systems may involve even more complicated mechanical components that are capable of stopping the engine and then restarting it later in an effort to improve fuel economy, or installing an electric motor to assist the combustion engine on demand.
Many companies also manufacture aftermarket flashing or tuning products that will reprogram the engine control computer with different calibrations, tables, curves and other operating parameters such as spark/timing, fuel settings, shift points, temperature conditions and other operating parameters and settings. Most systems of this kind are primarily designed to produce more horsepower, but some are advertised as useful to improve fuel economy. One of the drawbacks to such a system is that it permanently alters the engine control computer with a non-OEM/non-factory calibration that often cannot be serviced by repair shops and that usually voids the factory warranty on the engine.
Some companies also manufacture aftermarket exhaust valves, commonly referred to as a “cutout.” Some exhaust cutouts are electric in nature, allowing the vehicle operator to manually operate the cutout using a physical switch or button attached or connected to the cutout. These types of exhaust valves are always in an open position or a closed position, depending on the state of the physical switch or button used to operate them. Other exhaust cutouts are mechanical in nature, allowing the vehicle operator to manually operate the cutout using a physical lever or cable. Other mechanical exhaust cutouts use a block-off plate with bolts or fasteners that can be manually removed to alter exhaust flow or sound.
Other aftermarket exhaust products designed to work with OEM/factory installed exhaust flow control valves simply cut power to the entire exhaust flow control system to get it to change the state of the valve (as the valve usually has a different resting/power-off state from the active/power-on state), rather than directly controlling the valve itself. These kinds of systems are often limited because they cannot directly control the valve itself and by physically cutting power to the entire system, these systems may introduce trouble codes or faults into the vehicle.